GJT and YCC contributed equally to this work
Isolation and characterization of a termite transferrin gene up-regulated on infection
Version of Record online: 22 JAN 2003
Insect Molecular Biology
Volume 12, Issue 1, pages 1–7, February 2003
How to Cite
Thompson, G. J., Crozier, Y. C. and Crozier, R. H. (2003), Isolation and characterization of a termite transferrin gene up-regulated on infection. Insect Molecular Biology, 12: 1–7. doi: 10.1046/j.1365-2583.2003.00381.x
- Issue online: 22 JAN 2003
- Version of Record online: 22 JAN 2003
- Received 28 May 2002; accepted after revision 10 September 2002.
- insect immunity;
- tests for positive selection;
- subtractive hybridization;
PCR-based subtractive hybridization was used to isolate genes preferentially expressed in a termite (Mastotermes darwiniensis) following exposure to an entomopathogenic fungus. The subtraction procedure yielded a cDNA clone encoding a putative transferrin that, when sequenced to its ends, is the largest (728 amino acids) for any insect transferrin characterized to date. Cysteines and residues comprising putative iron-binding sites are conserved in both N- and C-terminal lobes, suggesting structural and functional similarity to diferric vertebrate transferrins. A quantitative PCR assay confirmed a significant increase in transferrin expression following infection, suggesting its up-regulation is part of the innate immune response. However, codon-based tests for selection among known insect transferrins revealed only a small proportion of codon-sites positively selected. Thus, unlike certain vertebrate transferrin lineages, no widespread evidence for pathogen-mediated positive selection was detected at this locus.